Referees' chief Mike Riley expects to see a spike in sanctions at the start of the season as clubs get used to the crackdown on dissent.

The head of the Professional Game Match Officials' Board believes it will take time before players fall into line regarding a new rule on aggression towards officials.

Last month the Premier League, EFL and Football Association ruled officials can now take a stricter approach if they are subjected to dissent, intimidation and physical contact from players or managers.

Should they feel it necessary they can issue an immediate yellow card to a player and Riley, who refereed in the Premier League between 1996 and 2009, believes it will take time before players and managers learn.

He told Press Association Sport: " Inevitably when you change anything there's a period of adjustment. Looking at videos goes so far but to be put into practice on the pitch it takes a while to become accustomed to. There may be a period of adjustment of a few weeks or a few matches.

"We had a similar initiative three or four years ago in Premier League games and, looking at the number of cautions in August and September, they increased. Then when everyone adjusted to it the cautions for the rest of the season reduced markedly.

"From the time the Premier League, the FA and the EFL announced the initiative there has been a lot of work to make sure the message gets out there. We have spoken to all the EFL managers and will have visited all the Premier League clubs before the start of the season."

Riley was talking ahead of the start of the EFL season, which begins when Newcastle travel to Fulham on Friday, with the Sky Bet Championship now having their own professional referees, k nown as Select Group 2.

Every Championship club has funded the move by pledging around £50,000 each which has allowed the introduction of 18 new contracted referees and 36 assistant referees.

Riley, who officiated at Euro 2004, said: "The game never stands still, every season speed of thought improves, skill levels and ability improves and we have to improve with them.

"The standard of refereeing in the Championship is good, given you have a group of referees who previously combined their passion for refereeing with having to work full-time and having their commitment to their family.

"What we learned from the creation of Select Group 1 (Premier League officials) in 2002 was if you allow people to focus on refereeing you have the time to dedicate to training. You organise the referees like you would players. Out of that we will be able to provide a lot better service to Championship clubs."

Riley also hopes the new group will provide a further avenue for players, with Doncaster defender Andy Butler studying to become a referee after he retires.

"One of the pieces of work we are doing with the PFA at the moment is looking at exactly that," he added. " Now you can aspire to a proper career as a Select Group 1 or 2 referee and that will encourage more people to come."